The present invention generally relates to implantation of a medical device or medication in a living body, and more particularly relates to an insertion tool for implanting a medical device or medication in a living body.
A variety of mechanisms exist for the implantation or injection of devices or medications within a living body. Items such as medicinal pellets or rods, contraceptive capsules, and sensors or identification transponders may be implanted at a target location within a human or other body. The associated procedures often employ multiple tools and/or specialized tools.
Known tools provide means for delivering an implant to a position determined by a surgeon or tool user as the correct location. Other tools are designed to deliver an implant to a position that is, in part, determined by the tool itself. For instance, mechanisms exist that control the angle of insertion or control the depth of insertion, and/or place the implant relative to the surface of the skin. With these tools, the site of tool insertion may still be determined by a surgeon, which may directly impact the final location of the implant. Still other procedures require a surgeon to determine the correct implant site using a first set of tools (which may or may not be invasive), and then to switch to the insertion tools required to deliver the implant. Unfortunately, the implant site determined by the first set of tools may not easily be located with the implant insertion tools.
Some implants, by their nature, do not require an exact location. For instance, a transponder that is injected into an animal may provide the intended tracking function, whether it is located under the skin of the ear, the neck, or the head. Other implants may require a higher degree of precision. This is the case for contraceptive rods that are implanted a specific distance from the surface of the skin, to facilitate later removal. Yet other implants require very precise placement in order to satisfy the intended function, such as devices using electrodes to stimulate specific nerves. If an electrode is not positioned close enough to stimulate the targeted nerve, additional surgery may be required.
While mechanisms exist for inserting or injecting implants in an approximate location (e.g., at a certain angle or depth), and other mechanisms exist for determining a target location for an implant, a need remains for a single, easy to use tool that is first used to determine or confirm the desired implant site and then reliably delivers the implant to that site. While procedures requiring very precise implant positioning will most benefit from such a tool, inserting implants requiring less precision will still find such a tool an improvement over the prior art mechanisms.
In addition, the implantation of microminiature, leadless stimulators called Bionic Neurons (also referred to as BIONs(trademark) microstimulators) heretofore would have required the use of multiple surgical instruments and/or instruments not ideally suited for the insertion of such a device. Therefore, a need also exists for a tool that locates and/or confirms the proper implant site for a BION stimulator, and then inserts the BION stimulator at that location.
As is ideal for any surgical tool, a tool that provides the above benefits should also be easy and evident to use, so that surgical time and possibility of error are both decreased. Also, the tool should limit the number and size of incisions required, to reduce the likelihood of infection, loss of blood, post-surgical pain, etc. The tool is preferably compact, light-weight and ergonomic, and constructed of materials that may be sterilized by standard methods known in the art (e.g., autoclave sterilization).
The present invention addresses the above and other needs by providing an insertion tool for a miniature implantable stimulator or other implantable device or medication.
The insertion tool of the present invention preferably applies to microminiature, leadless stimulators called BION(trademark) stimulators or BION microstimulators or BION implants or BION devices. However, the invention may also be used to implant other devices or to insert a medicament. For use with a BION stimulator, the components of the tool preferably include a cannula which is used in conjunction with the remaining components to determine and/or confirm the proper implant location and then deliver the stimulator to that precise location.
In a primary embodiment, a trocar, scalpel, or other standard instrument is used to facilitate entry through the skin. A stimulating probe is inserted into the cannula of the tool and is used to bluntly dissect to the implant area. With the probe tip at a probable implant site, electrical impulses are delivered to the probe tip to test the area and determine and/or confirm the desired implant site. Once an acceptable site is found, the stimulating probe is removed from the cannula, and an implant holder containing a BION stimulator is inserted into the cannula. The implant is packaged and provided in the implant holder, which ensures proper electrical polarity, and helps protect and ease handling of the BION device.
A push rod assembly is positioned with the rod in the implant holder tube, so the distal end of the rod abuts the proximal end of the implant. The BION microstimulator is tested to ensure proper operation and position. Mating mechanisms on the implant holder and push rod assembly are utilized to pull the implant holder proximally from around the implant, while the push rod keeps the implant in position. With the implant holder thus retracted, the tool is removed, leaving the implant precisely in the proper location.
Other embodiments of the invention include various methods and tool configurations for determining and/or confirming a proper implant site. In addition, alternative mechanisms and methods for removal of the implant holder from around the implant are described, as are alternatives for streamlined use with the BION stimulator or with implants other than a microstimulator.